KR20240009387A - Manufacturing method of high-capacity low-voltage electrode foil for automotive electronics - Google Patents

Abstract

The present invention relates to a method of manufacturing a high-capacity low-voltage electrode foil for automotive electronics. First, the first-stage forming, second-stage forming, third-stage forming, and fourth-stage forming operations are sequentially performed on the corrosion foil, and a single-round forming process is performed. The voltage, temperature, time, chemical composition, and mixing ratio used are adjusted, and an amine treatment liquid is added during the first stage of chemical conversion to significantly increase the content of aluminum oxide crystals in the formed oxide film. Then, the chemical conversion foil is phosphated several times. It includes a step of repairing defects remaining on the molded oxide film by immersing it in a solution and performing a post-treatment operation. In this way, not only can the boiling life of the electrode foil be effectively improved, but the specific capacitance of the aluminum electrode foil can also be greatly improved.

Description

Manufacturing method of high-capacity low-voltage electrode foil for automotive electronics

The present invention relates to the field of electrode foil manufacturing technology, and more specifically, to a method for manufacturing high-specific capacity, low-voltage electrode foils for automotive electronics.

Today, the level of electrification of automobiles is continuously increasing worldwide. In particular, as the level of intelligence, networking, and electrification of automobiles continues to increase due to the development of electric vehicles and autonomous driving, the use of electronic components in automobiles is increasing. The capacitors used in automotive electronic systems are of various types, large in quantity, high quality standards, and the development prospects of capacitors have become broader. Capacitors are basic components of automotive electronic components and play an important role in the development of automotive electronic components. Capacitors that are compact, have a long lifespan, and are highly reliable are helpful in integrating and diversifying automotive electronic design, and improving the capacity of electrode foils is a key point in realizing miniaturization and high performance of aluminum electrolytic capacitors.

Currently, electrode foils are generally manufactured by adopting a multi-step chemical conversion method. This generally consists of four stages of harmony. Step 1: 7% ammonium adipate, 1% borate, temperature 70°C, time 7 minutes, water washing; Step 2: 5% ammonium adipate, 1% borate, temperature 70°C, time 6 minutes; Step 3: 3% ammonium adipate, 1% borate, temperature 70°C, time 8 minutes, water washing; Stage 4 Formation: 5% phosphate, temperature 70°C, time 15 minutes; After 1st time: 1% phosphate, temperature 80℃, time 12 minutes, wash with water, pour into 7% phosphoric acid solution, time 5 minutes, wash with water, high temperature (450 to 500℃) treatment for 1.5 minutes, then 2nd time: 3% Phosphate, temperature 70°C, time 5 min; After the 3rd time: 1% phosphate, temperature 70℃, time 5.5 minutes, water washing and drying. Although the manufacturing process is simple and low cost, the capacitance and boiling life of the manufactured electrode foil are low, and the defect rate is still high. This is because the content of aluminum oxide crystals in the oxide film on the surface of the electrode foil is low and many defect points remain in the oxide film after chemical treatment, so those skilled in the art urgently need to solve the above problems.

Therefore, the designer of the present invention took into account the above-mentioned existing problems and defects, collected related data, evaluated and considered various aspects, and continued experiments and modifications by technicians with many years of research and development experience in the industry. , Finally, we propose a method for manufacturing the high-capacity low-voltage electrode foil for automotive electronics.

In order to solve the above technical problems, the present invention relates to a method of manufacturing a high-specific capacity, low-voltage electrode foil for automotive electronics, and includes the following steps.

Preparation of S1 corrosion foil: Aluminum foil with a purity of 99.9% or higher is immersed in an acidic solution and the surface is corroded.

S2 is a multi-stage harmonization, including the following sub-stages.

S21 Stage 1 conversion: The corrosion foil obtained in step S1 is immersed in a mixed solution containing 5 to 10 wt% ammonium sulfate, 1 to 2 wt% borate and 0.5 to 1 wt% amine salt, the temperature being controlled at 65 to 85° C., 20 The conversion is performed under a voltage of 160 V to 160 V, and the time is controlled to 5 to 10 minutes to produce a first-stage conversion foil.

S22 Surface cleaning: The first-stage conversion foil obtained in step S21 is subjected to water washing and air drying.

S23 Second-stage conversion: The first-stage conversion foil treated through step S22 is immersed in a mixed solution containing 3 to 7 wt% ammonium sulfate and 1 to 2 wt% borate, temperature controlled at 65 to 85° C., voltage 20 to 160 V. A two-step chemical conversion foil is manufactured by performing conversion under the following conditions and controlling the time to 5 to 10 minutes.

S24 3-step conversion: The 2-step conversion foil obtained in step S23 is immersed in a mixed solution containing 3 to 5 wt% ammonium sulfate and 1 to 2 wt% borate, the temperature of which is controlled at 65 to 85° C., under a voltage of 20 to 160 V. The conversion is performed and the time is controlled from 7 to 15 minutes to produce a three-stage conversion foil.

S25 Surface cleaning: The three-stage conversion foil obtained in step S24 is subjected to water washing and air drying.

S26 Intermediate treatment: The three-stage conversion foil treated in step S25 is immersed in an aqueous solution of 5 to 10 wt% of quaternary ammonium salt, the temperature of which is controlled at 40 to 60° C., and the time is controlled to be 5 to 10 minutes.

S27 4-step conversion: The 3-step conversion foil obtained in step S26 is immersed in a solution containing 5 to 7 wt% phosphate, the temperature of which is controlled at 65 to 85 ° C., and conversion is performed under a voltage of 20 to 160 V, and the time is 15 Controlled from 1 to 20 minutes, a 4-step chemical conversion foil is produced.

S3 post-processing: includes the following substeps:

S31 1st stage post-treatment: The 4th stage chemical conversion foil obtained in step S27 is immersed in a 1 to 5 wt% phosphate aqueous solution whose temperature is controlled at 65 to 85°C, a voltage of 20 to 160V is applied, and the time is 10 to 15 minutes. Manufacture a first-stage processing foil by controlling.

S32 Surface cleaning: Water washing and air drying are performed on the first-stage treated foil obtained in step S31.

S33 Acid soak treatment: The first-stage treatment foil treated in step S32 is immersed in a mixed solution containing 7 to 10 wt% phosphoric acid and oxidizing acid, and the time is controlled to 5 to 10 minutes.

S34 heat treatment: Water washing and drying operations are performed on the first-stage treated foil obtained in step S33, the drying temperature is controlled to 450 to 500 ° C., and the time is controlled to 1 to 2 minutes.

S35 2nd stage post-treatment: The 1st stage treated foil obtained in step S34 is immersed in 1 to 5 wt% phosphate aqueous solution whose temperature is controlled at 65 to 85°C, a voltage of 20 to 160V is applied, and the time is 5 to 10 minutes. Manufacture a two-step processing foil by controlling.

S36 3-step post-treatment: The 2-step treatment foil obtained in step S35 is immersed in 1 to 5 wt% phosphate aqueous solution whose temperature is controlled at 65 to 85°C, a voltage of 20 to 160 V is applied, and the time is 5 to 10 minutes. Manufacture a three-step processing foil by controlling.

S37 Surface cleaning: Water washing and air drying operations are performed on the three-stage treated foil obtained in step S36 to obtain a high specific capacity low voltage electrode foil.

More preferably, in the technical solution disclosed in the present invention, the borate is preferably any one of borax, sodium metaborate, or a mixture thereof.

More preferably in the technical solution disclosed in the present invention, the amine salt is preferably hexylbenzylamine salt, dicyclohexylamine salt, BOC-HIS(BOC)-OH DCHA, dimethylamine hydrochloride, triethanolamine, piroctone ol. It is any one of amines or a mixture thereof.

More preferably in the technical solution disclosed in the present invention, the quaternary ammonium salt is preferably any one of sodium dodecyl sulfate, dodecyltrimethylammonium bromide, dodecyl alcohol ether ammonium sulfate, or a mixture thereof.

More preferably in the technical solution disclosed in the present invention, the phosphate salt is preferably any one of diammonium phosphate, sodium hexametaphosphate, disodium hydrogen phosphate, or a mixture thereof.

More preferably, in the technical solution disclosed in the present invention, the oxidizing acid is preferably any one of nitric acid, permanganic acid, and hypochlorous acid, and the ratio of the mixed acid by weight is phosphoric acid:oxidizing acid = 2:1.

In actual industrial applications, the manufacturing method of high-capacity low-voltage electrode foil for automotive electronics achieves at least several beneficial effects:

1) Whether it is the 1st stage formation, 2nd stage formation, 3rd stage formation or 4th stage formation stage, a constant density of current is applied to the conversion tank liquid, so that the oxide film is stably and quickly created on the surface of the corrosion foil, and within different areas. It ensures that the distribution shape of the formed holes is more balanced.

2) By adjusting the voltage, temperature, time, components of the chemical solution used, and mixing ratio for each chemical conversion step, the density of each layer of the molded oxide film is made consistent, helping to improve the boiling life of the electrode foil. .

3) In step S21, the content of γ` or γ-Al ₂ O ₃ in the oxide film can be increased by adding an amine treatment solution during the first stage chemical conversion. This is because a monohydrate boehmite deposition film is formed on the microporous surface of the corrosion foil in a slightly alkaline environment, and is inevitably decomposed after subsequent high temperature treatment to produce γ′ or γ-Al ₂ O ₃ .

4) In the subsequent treatment step, defect points formed on the oxide film during chemical conversion (exposed after acid immersion or high temperature treatment) are repaired, which helps extend the boiling life.

In order to more clearly explain the embodiments of the present invention or the technical solutions of the prior art, the following briefly introduces the accompanying drawings to be used in the description of the embodiments or the prior art, and the accompanying drawings in the following description are among the embodiments of the present invention. These are only some of the drawings, and it will be clear that a person skilled in the art can obtain other attached drawings without creative effort based on these attached drawings.
1 is a photo of the metal structure of a molded electrode foil manufactured by the general multi-step conversion described in the background art.
Figure 2 is a photograph of the metal structure of the molded electrode foil manufactured using the method of Example 1.
Figure 3 is a photograph of the metal structure of the molded electrode foil manufactured using the method of Example 2.
Figure 4 is a photograph of the metal structure of the molded electrode foil manufactured using the method of Example 3.
Figure 5 is a photograph of the metal structure of the molded electrode foil manufactured using the method of Example 4.

In order to facilitate understanding of the present invention, the present invention will be described in more detail below through examples, and the examples are for interpreting the present invention and do not limit the scope of protection of the present invention. The methods described are all general methods unless otherwise specified.

Comparative Example 1

The electrode foil is manufactured with reference to the multi-step forming method disclosed in the background art described above.

Example 1

A method of manufacturing a high-capacity low-voltage electrode foil for automotive electronics includes the following steps.

Preparation of S1 corrosion foil: Aluminum foil with a purity of 99.9% or higher and a thickness of 100 μm is immersed in an acidic solution and the surface is corroded.

S2 is a multi-stage harmonization, including the following sub-stages.

S21 Step 1 formation: The corrosion foil obtained in Step S1 is immersed in a mixed solution containing 5 wt% ammonium sulfate, 1 wt% sodium metaborate and 0.5 wt% hexylbenzylamine salt, the temperature of which is controlled at 65 to 85°C, and the temperature is controlled at 65 to 85° C. Formation is performed under a voltage of 160V, and the time is controlled to 10 minutes to produce a first-stage conversion foil.

S22 Surface cleaning: The first-stage conversion foil obtained in step S21 is subjected to water washing and air drying (air drying temperature is 20° C. or lower).

S23 Second-stage conversion: The first-stage conversion foil treated through step S22 is immersed in a mixed solution containing 3 wt% ammonium sulfate and 1 wt% sodium metaborate, the temperature of which is controlled at 65 to 85°C, and converted under a voltage of 20 to 160 V. is performed, and the time is controlled to 10 minutes to produce a second-stage chemical conversion foil.

S24 3-step conversion: The 2-step conversion foil obtained in step S23 is immersed in a mixed solution containing 3 wt% ammonium sulfate and 1 wt% sodium metaborate, the temperature of which is controlled at 65 to 85° C., and conversion is performed under a voltage of 20 to 160 V. The process is performed, and the time is controlled to 15 minutes to produce a three-stage chemical conversion foil.

S25 Surface cleaning: The three-stage conversion foil obtained in step S24 is subjected to water washing and air drying.

S26 Intermediate treatment: The three-stage conversion foil treated in step S25 is immersed in a 5 wt% aqueous solution of sodium dodecyl sulfate, the temperature of which is controlled at 40 to 60° C., and the time is controlled at 10 minutes.

S27 4-step conversion: The 3-step conversion foil obtained in step S26 is immersed in a solution containing 5 wt% sodium hexametaphosphate, the temperature of which is controlled at 65 to 85° C., and conversion is performed under a voltage of 20 to 160 V, and the time is Controlled to 20 minutes, a 4-step conversion foil is manufactured.

S3 post-processing: includes the following substeps:

S31 1st stage post-treatment: The 4th stage chemical conversion foil obtained in step S27 is immersed in 1 wt% sodium hexametaphosphate aqueous solution whose temperature is controlled at 65 to 85°C, a voltage of 20 to 160V is applied, and the time is 15 minutes. Control to produce a first-stage processed foil.

S32 Surface cleaning: Water washing and air drying are performed on the first-stage treated foil obtained in step S31.

S33 acid soak treatment: The first-stage treatment foil treated in step S32 is immersed in an acidic mixed solution of 7 wt% phosphoric acid:perchloric acid at a ratio of 1:1, and the time is controlled to 6 minutes.

S34 heat treatment: Water washing and drying operations are performed on the first-stage treated foil obtained in step S33, the drying temperature is controlled to 450 to 500 ° C., and the time is controlled to 1.5 minutes.

S35 Second-stage post-treatment: The first-stage treatment foil obtained in step S34 is immersed in a 1 wt% sodium hexametaphosphate aqueous solution whose temperature is controlled at 65 to 85 ° C., a voltage of 20 to 160 V is applied, and the time is 10 minutes. Control the two-stage processing foil.

S36 3-step post-treatment: The 2-step treatment foil obtained in step S35 is immersed in a 1 wt% sodium hexametaphosphate aqueous solution whose temperature is controlled at 65 to 85 ° C., a voltage of 20 to 160 V is applied, and the time is 10 minutes. Control the three-stage processing foil.

S37 Surface cleaning: Water washing and air drying operations are performed on the three-stage treated foil obtained in step S36 to obtain a high specific capacity low voltage electrode foil.

Example 2

A method of manufacturing a high-capacity low-voltage electrode foil for automotive electronics includes the following steps.

Preparation of S1 corrosion foil: Aluminum foil with a purity of 99.9% or higher and a thickness of 100 μm is immersed in an acidic solution and the surface is corroded.

S2 is a multi-stage harmonization, including the following sub-stages.

S21 Stage 1 formation: The corrosion foil obtained in step S1 is immersed in a mixed solution containing 8 wt% ammonium sulfate, 1.5 wt% sodium metaborate and 0.7 wt% hexylbenzylamine salt, temperature controlled at 65 to 85° C., 20 The conversion is performed under a voltage of 160 V to 160 V, and the time is controlled to 10 minutes to produce a first-stage conversion foil.

S22 Surface cleaning: The first-stage conversion foil obtained in step S21 is subjected to water washing and air drying (air drying temperature is 20° C. or lower).

S23 Second-stage conversion: The first-stage conversion foil treated through step S22 is immersed in a mixed solution containing 5 wt% ammonium sulfate and 1.5 wt% sodium metaborate, the temperature of which is controlled at 65 to 85° C., under a voltage of 20 to 160 V. The conversion is performed and the time is controlled to 10 minutes to produce a two-stage conversion foil.

S24 3-step conversion: The 2-step conversion foil obtained in step S23 is immersed in a mixed solution containing 4 wt% ammonium sulfate and 1.5 wt% sodium metaborate, the temperature of which is controlled at 65 to 85° C., and converted under a voltage of 20 to 160 V. is performed, and the time is controlled to 15 minutes to produce a 3-step chemical conversion foil.

S25 Surface cleaning: The three-stage conversion foil obtained in step S24 is subjected to water washing and air drying.

S26 Intermediate treatment: The three-stage conversion foil treated in step S25 is immersed in an 8 wt% aqueous solution of sodium dodecyl sulfate, the temperature of which is controlled to 40 to 60 ° C., and the time is controlled to 10 minutes.

S27 4-step conversion: The 3-step conversion foil obtained in step S26 is immersed in a solution containing 6 wt% sodium hexametaphosphate, the temperature of which is controlled at 65 to 85° C., and conversion is performed under a voltage of 20 to 160 V, and the time is Controlled to 20 minutes, a 4-step conversion foil is manufactured.

S3 post-processing: includes the following substeps:

S31 1st stage post-treatment: The 4th stage chemical conversion foil obtained in step S27 is immersed in a 3wt% sodium hexametaphosphate aqueous solution whose temperature is controlled at 65 to 85°C, a voltage of 20 to 160V is applied, and the time is 15 minutes. Control to produce a first-stage processed foil.

S32 Surface cleaning: Water washing and air drying are performed on the first-stage treated foil obtained in step S31.

S33 acid soak treatment: The first-stage treatment foil treated in step S32 is immersed in an acidic mixed solution of 8 wt% phosphoric acid:perchloric acid at a ratio of 1:1, and the time is controlled to 6 minutes.

S34 heat treatment: Water washing and drying operations are performed on the first-stage treated foil obtained in step S33, the drying temperature is controlled to 450 to 500 ° C., and the time is controlled to 1.5 minutes.

S35 Second-stage post-treatment: The first-stage treatment foil obtained in step S34 is immersed in a 3 wt% sodium hexametaphosphate aqueous solution whose temperature is controlled at 65 to 85 ° C., a voltage of 20 to 160 V is applied, and the time is 10 minutes. Control the two-stage processing foil.

S36 3-step post-treatment: The 2-step treatment foil obtained in step S35 is immersed in a 3 wt% sodium hexametaphosphate aqueous solution whose temperature is controlled at 65 to 85 ° C., a voltage of 20 to 160 V is applied, and the time is 10 minutes. Control the three-stage processing foil.

S37 Surface cleaning: Water washing and air drying operations are performed on the three-stage treated foil obtained in step S36 to obtain a high specific capacity low voltage electrode foil.

Example 3

A method of manufacturing a high-capacity low-voltage electrode foil for automotive electronics includes the following steps.

Preparation of S1 corrosion foil: Aluminum foil with a purity of 99.9% or higher and a thickness of 100 μm is immersed in an acidic solution and the surface is corroded.

S2 is a multi-stage harmonization, including the following sub-stages.

S21 Stage 1 formation: The corrosion foil obtained in step S1 is immersed in a mixed solution containing 10 wt% ammonium sulfate, 2 wt% sodium metaborate and 1 wt% hexylbenzylamine salt, temperature controlled at 65 to 85° C., 20 to 160 V. Formation is performed under voltage, and the time is controlled to 10 minutes to produce a first-stage conversion foil.

S22 Surface cleaning: The first-stage conversion foil obtained in step S21 is subjected to water washing and air drying (air drying temperature is 20° C. or lower).

S23 Second-stage conversion: The first-stage conversion foil treated through step S22 is immersed in a mixed solution containing 7 wt% ammonium sulfate and 2 wt% sodium metaborate, the temperature of which is controlled at 65 to 85°C, and converted under a voltage of 20 to 160 V. is performed, and the time is controlled to 10 minutes to produce a second-stage chemical conversion foil.

S24 3-step conversion: The 2-step conversion foil obtained in step S23 is immersed in a mixed solution containing 5 wt% ammonium sulfate and 2 wt% sodium metaborate, the temperature of which is controlled at 65 to 85° C., and conversion is performed under a voltage of 20 to 160 V. The process is performed, and the time is controlled to 15 minutes to produce a three-stage chemical conversion foil.

S25 Surface cleaning: The three-stage conversion foil obtained in step S24 is subjected to water washing and air drying.

S26 Intermediate treatment: The three-stage conversion foil treated in step S25 is immersed in a 10 wt% aqueous solution of sodium dodecyl sulfate, the temperature of which is controlled at 40 to 60° C., and the time is controlled at 10 minutes.

S27 4-step conversion: The 3-step conversion foil obtained in step S26 is immersed in a solution containing 7 wt% sodium hexametaphosphate, the temperature of which is controlled at 65 to 85° C., and conversion is performed under a voltage of 20 to 160 V, and the time is Controlled to 20 minutes, a 4-step conversion foil is manufactured.

S3 post-processing: includes the following substeps:

S31 1st stage post-treatment: The 4th stage chemical conversion foil obtained in step S27 is immersed in a 5 wt% sodium hexametaphosphate aqueous solution whose temperature is controlled at 65 to 85°C, a voltage of 20 to 160V is applied, and the time is 15 minutes. Control to produce a first-stage processed foil.

S32 Surface cleaning: Water washing and air drying are performed on the first-stage treated foil obtained in step S31.

S33 acid soak treatment: The first-stage treatment foil treated in step S32 is immersed in an acidic mixed solution of 10 wt% phosphoric acid:perchloric acid at a ratio of 1:1, and the time is controlled to 6 minutes.

S34 heat treatment: Water washing and drying operations are performed on the first-stage treated foil obtained in step S33, the drying temperature is controlled to 450 to 500 ° C., and the time is controlled to 1.5 minutes.

S35 Second-stage post-treatment: The first-stage treatment foil obtained in step S34 is immersed in a 5 wt% sodium hexametaphosphate aqueous solution whose temperature is controlled at 65 to 85 ° C., a voltage of 20 to 160 V is applied, and the time is 10 minutes. Control the two-stage processing foil.

S36 3-step post-treatment: The 2-step treatment foil obtained in step S35 is immersed in a 5 wt% sodium hexametaphosphate aqueous solution whose temperature is controlled at 65 to 85 ° C., a voltage of 20 to 160 V is applied, and the time is 10 minutes. Control the three-stage processing foil.

S37 Surface cleaning: Water washing and air drying operations are performed on the three-stage treated foil obtained in step S36 to obtain a high specific capacity low voltage electrode foil.

Example 4

A method of manufacturing a high-capacity low-voltage electrode foil for automotive electronics includes the following steps.

Preparation of S1 corrosion foil: Aluminum foil with a purity of 99.9% or higher and a thickness of 100 μm is immersed in an acidic solution and the surface is corroded.

S2 is a multi-stage harmonization, including the following sub-stages.

S21 Step 1 formation: The corrosion foil obtained in Step S1 is immersed in a mixed solution containing 5 wt% ammonium sulfate, 1 wt% sodium metaborate and 0.5 wt% hexylbenzylamine salt, the temperature of which is controlled at 65 to 85°C, and the temperature is controlled at 65 to 85° C. Formation is performed under a voltage of 160V, and the time is controlled to 5 minutes to produce a first-stage conversion foil.

S22 Surface cleaning: The first-stage conversion foil obtained in step S21 is subjected to water washing and air drying (air drying temperature is 20° C. or lower).

S23 Second-stage conversion: The first-stage conversion foil treated through step S22 is immersed in a mixed solution containing 3 wt% ammonium sulfate and 1 wt% sodium metaborate, the temperature of which is controlled at 65 to 85°C, and converted under a voltage of 20 to 160 V. is performed, and the time is controlled to 5 minutes to produce a two-stage chemical conversion foil.

S24 3-step conversion: The 2-step conversion foil obtained in step S23 is immersed in a mixed solution containing 3 wt% ammonium sulfate and 1 wt% sodium metaborate, the temperature of which is controlled at 65 to 85° C., and conversion is performed under a voltage of 20 to 160 V. The process is performed, and the time is controlled to 7 minutes to produce a three-stage chemical conversion foil.

S25 Surface cleaning: The three-stage conversion foil obtained in step S24 is subjected to water washing and air drying.

S26 Intermediate treatment: The three-stage conversion foil treated in step S25 is immersed in a 5 wt% aqueous solution of sodium dodecyl sulfate, the temperature of which is controlled at 40 to 60° C., and the time is controlled at 10 minutes.

S27 4-step conversion: The 3-step conversion foil obtained in step S26 is immersed in a solution containing 5 wt% sodium hexametaphosphate, the temperature of which is controlled at 65 to 85° C., and conversion is performed under a voltage of 20 to 160 V, and the time is Controlled to 15 minutes, a four-step chemical foil is manufactured.

S3 post-processing: includes the following substeps:

S31 1st stage post-treatment: The 4th stage chemical conversion foil obtained in step S27 is immersed in 1 wt% sodium hexametaphosphate aqueous solution whose temperature is controlled at 65 to 85°C, a voltage of 20 to 160V is applied, and the time is 10 minutes. Control the first-stage processing foil.

S32 Surface cleaning: Water washing and air drying are performed on the first-stage treated foil obtained in step S31.

S33 acid soak treatment: The first-stage treatment foil treated in step S32 is immersed in an acidic mixed solution of 7 wt% phosphoric acid:perchloric acid at a ratio of 1:1, and the time is controlled to 6 minutes.

S34 heat treatment: Water washing and drying operations are performed on the first-stage treated foil obtained in step S33, the drying temperature is controlled to 450 to 500 ° C., and the time is controlled to 1.5 minutes.

S35 Second-stage post-treatment: The first-stage treatment foil obtained in step S34 is immersed in a 1 wt% sodium hexametaphosphate aqueous solution whose temperature is controlled at 65 to 85 ° C., a voltage of 20 to 160 V is applied, and the time is 5 minutes. Control the two-stage processing foil.

S36 3-step post-treatment: The 2-step treatment foil obtained in step S35 is immersed in a 1 wt% sodium hexametaphosphate aqueous solution whose temperature is controlled at 65 to 85 ° C., a voltage of 20 to 160 V is applied, and the time is 5 minutes. Control the three-step processing foil.

S37 Surface cleaning: Water washing and air drying operations are performed on the three-stage treated foil obtained in step S36 to obtain a high specific capacity low voltage electrode foil.

As can be seen from the comparative analysis of Figures 1 and Figures 2, 3, 4, and 5, the porosity of the manufactured electrode foil is significantly improved, the average particle diameter is smaller, and the distribution shape is more uniform, resulting in a higher electrical performance index of the electrode foil. It helps to further improve. In addition, through specific experimental results, it was confirmed that the electrode foil voltage resistance performance and electric capacity were effectively improved, and the boiling step-up time was significantly shortened (specific performance test data are shown in Table 1).

Table 1 summarizes the performance test results of the electrode foils obtained in Comparative Examples and Examples 1 to 4.

Table 1

Vfe - the final voltage applied when performing a forming process on an unoxidized foil;

Vt - the withstand voltage value of the Mars foil;

The reason for this is as follows.

1) Whether it is the 1st stage formation, 2nd stage formation, 3rd stage formation or 4th stage formation stage, a constant density of current is applied to the conversion tank liquid, so that the oxide film is stably and quickly created on the surface of the corrosion foil, and within different areas. It ensures that the distribution shape of the formed holes is more balanced.

2) For each chemical conversion step, by adjusting the voltage, temperature, time, components of the chemical liquid used, and mixing ratio, the density of each layer of the molded oxide film is made consistent, helping to improve the boiling life of the electrode foil. .

3) In step S21, the content of γ` or γ-Al ₂ O ₃ in the oxide film can be increased by adding an amine treatment solution during the first stage chemical conversion. This is because a monohydrate boehmite deposition film is formed on the microporous surface of the corrosion foil in a slightly alkaline environment, and is inevitably decomposed after subsequent high temperature treatment to produce γ′ or γ-Al ₂ O ₃ .

Here, it should be noted that in the post-processing step, defect points formed on the oxide film during chemical conversion (acid immersion or exposure after high-temperature treatment) can be effectively and sufficiently repaired, and the specific capacitance of the aluminum electrode foil can be significantly improved.

The principle is briefly explained as follows: In the post-treatment stage, upon acid treatment:

anode

cathode

Due to the presence of strong oxidizing acids, the cathode:

At the interface of the two phases, the decrease in acidity causes the deposition of phosphate films of Al ³⁺ and Mn ²⁺ while at the same time the deposition of monohydrate boehmite structures occurs, realizing electrode foil surface repair.

The formed chemically modified film contained γ' or γ-Al ₂ O ₃ component in its bottom layer even without high temperature treatment, and the aluminum oxide crystal content in the oxide film increased. Since the dielectric constant of crystalline Al ₂ O ₃ is higher than that of amorphous Al ₂ O ₃ , the content of crystalline Al ₂ O ₃ in the dielectric film is effectively increased, which serves as a cornerstone for significantly increasing the specific capacitance of the aluminum electrode foil.

Lastly, keep in mind a few things:

1) When performing chemical treatment on a corrosion foil, in addition to the sodium metaborate disclosed in the above examples, borates such as borax and a mixture of sodium metaborate and borax may be preferably selected depending on the actual situation.

2) In carrying out the chemical treatment of the corrosion foil, in addition to the hexylbenzylamine salt disclosed in the above examples, dicyclohexylamine salt, BOC-HIS(BOC)-OH DCHA, dimethylamine hydrochloride, triethanolamine, Any one of amine salts such as piroctone olamine or a mixture thereof may be preferably selected.

3) In carrying out the chemical treatment of the corrosion foil, in addition to the sodium dodecyl sulfate disclosed in the above examples, any one of quaternary ammonium salts such as dodecyltrimethylammonium bromide and dodecyl alcohol ether ammonium sulfate or a mixture thereof may be used depending on the actual situation. You may select it as desired.

4) In the process of performing post-treatment on the chemical conversion foil, in addition to the sodium hexametaphosphate disclosed in the above examples, any one of phosphates such as diammonium phosphate and disodium hydrogen phosphate, or a mixture thereof, may be preferably selected depending on the actual situation. there is.

The foregoing description of the disclosed embodiments enables any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Accordingly, the present invention is not limited to the embodiments disclosed herein but is subject to the widest scope consistent with the principles and novel features disclosed herein.

Claims (6)

In the manufacturing method of high-capacity low-voltage electrode foil for automotive electronics,
The following steps,
Preparation of S1 corrosion foil: Aluminum foil with a purity of 99.9% or higher is immersed in an acidic solution to corrode the surface;
multi-stage harmony with sub-stages S2 and below;
S21 Stage 1 conversion: The corrosion foil obtained in step S1 is immersed in a mixed solution containing 5 to 10 wt% ammonium sulfate, 1 to 2 wt% borate and 0.5 to 1 wt% amine salt, the temperature being controlled at 65 to 85° C., 20 The conversion is performed under a voltage of 160 V to 160 V, and the time is controlled to 5 to 10 minutes to produce a first-stage conversion foil;
S22 Surface cleaning: water washing and air drying are performed on the first-stage conversion foil obtained in step S21;
S23 Second-stage conversion: The first-stage conversion foil treated through step S22 is immersed in a mixed solution containing 3 to 7 wt% ammonium sulfate and 1 to 2 wt% borate, temperature controlled at 65 to 85° C., voltage 20 to 160 V. A two-stage chemical conversion foil is manufactured by performing conversion under the following conditions and controlling the time to 5 to 10 minutes;
S24 3-step conversion: The 2-step conversion foil obtained in step S23 is immersed in a mixed solution containing 3 to 5 wt% ammonium sulfate and 1 to 2 wt% borate, the temperature of which is controlled at 65 to 85° C., under a voltage of 20 to 160 V. Carry out conversion and control the time between 7 and 15 minutes to produce a three-stage conversion foil;
S25 Surface cleaning: water washing and air drying are performed on the three-stage conversion foil obtained in step S24;
S26 intermediate treatment: the three-stage chemical conversion foil treated in step S25 is immersed in a 5 to 10 wt% aqueous quaternary ammonium salt solution, the temperature of which is controlled at 40 to 60° C., and the time is controlled to be 5 to 10 minutes;
S27 4-step conversion: The 3-step conversion foil obtained in step S26 is immersed in a solution containing 5 to 7 wt% phosphate, the temperature of which is controlled at 65 to 85 ° C., and conversion is performed under a voltage of 20 to 160 V, and the time is 15 to 20 minutes to prepare a four-step conversion foil;
Post-processing including substeps below S3
S31 1st stage post-treatment: The 4th stage chemical conversion foil obtained in step S27 is immersed in a 1 to 5 wt% phosphate aqueous solution whose temperature is controlled at 65 to 85°C, a voltage of 20 to 160V is applied, and the time is 10 to 15 minutes. Manufacture a first-stage processing foil by controlling;
S32 Surface cleaning: water washing and air drying are performed on the first-stage treated foil obtained in step S31;
S33 acid soak treatment: the first-stage treatment foil treated in step S32 is immersed in a mixed solution containing 7 to 10 wt% phosphoric acid and oxidizing acid, and the time is controlled to 5 to 10 minutes;
S34 heat treatment: water washing and drying operations are performed on the first-stage treated foil obtained in step S33, the drying temperature is controlled to 450 to 500 ° C., and the time is controlled to 1 to 2 minutes;
S35 2nd stage post-treatment: The 1st stage treated foil obtained in step S34 is immersed in 1 to 5 wt% phosphate aqueous solution whose temperature is controlled at 65 to 85°C, a voltage of 20 to 160V is applied, and the time is 5 to 10 minutes. Manufacture a two-step processing foil by controlling;
S36 3-step post-treatment: The 2-step treatment foil obtained in step S35 is immersed in 1 to 5 wt% phosphate aqueous solution whose temperature is controlled at 65 to 85°C, a voltage of 20 to 160 V is applied, and the time is 5 to 10 minutes. Manufacture a three-step processing foil by controlling;
S37 Surface cleaning: performing water washing and air drying on the 3-step treated foil obtained in step S36 to obtain a high specific capacity low voltage electrode foil. High specific capacity low voltage electrode foil for automotive electronics, comprising: Manufacturing method. According to paragraph 1,
A method of manufacturing a high specific capacity low voltage electrode foil for automotive electronics, wherein the borate is either borax or sodium metaborate or a mixture thereof. According to paragraph 1,
The amine salt is for automotive electronics, characterized in that it is any one of hexylbenzylamine salt, dicyclohexylamine salt, BOC-HIS(BOC)-OH DCHA, dimethylamine hydrochloride, triethanolamine, and piroctone olamine, or a mixture thereof. Method for manufacturing high specific capacity low voltage electrode foil. According to paragraph 1,
A method for producing a high-specific capacity low-voltage electrode foil for automotive electronics, wherein the quaternary ammonium salt is any one of sodium dodecyl sulfate, dodecyltrimethylammonium bromide, and dodecyl alcohol ether ammonium sulfate, or a mixture thereof. According to paragraph 1,
A method of manufacturing a high-specific capacity low-voltage electrode foil for automotive electronics, wherein the phosphate is any one of diammonium phosphate, sodium hexametaphosphate, and disodium hydrogen phosphate, or a mixture thereof. According to paragraph 1,
The oxidizing acid is one of nitric acid, permanganic acid, and hypochlorous acid, and the ratio of the mixed acid based on weight is phosphoric acid:oxidizing acid = 2:1. A method of manufacturing a high-specific capacity low-voltage electrode foil for automotive electronics.